Evidence for Interface-Rate Limited Densification Kinetics at Al2O3-GdAlO3 Interfaces Characterized by in situ Ultrahigh Temperature Transmission Electron Microscopy
Evidence for Interface-Rate Limited Densification Kinetics at Al2O3-GdAlO3 Interfaces Characterized by in situ Ultrahigh Temperature Transmission Electron Microscopy
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DOI：
10.1016/j.jeurceramsoc.2022.06.001
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发表时间：
2022-06
影响因子：
5.7
通讯作者：
D. Coffman;Yong Ma;C. Barr;J. Ouyang;K. Hattar;S. Dillon
中科院分区：
文献类型：
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作者：
D. Coffman;Yong Ma;C. Barr;J. Ouyang;K. Hattar;S. Dillon
采用透射电镜原位成像技术研究了单个Al 2 O3颗粒在GdAlO 3上的烧结行为。在双晶实验中，具有较低Al 2 O3-GdAlO 3相边界能的颗粒通过奥斯特瓦尔德熟化收缩，没有证据表明致密化是由沿界面沿着的原子通量引起的。具有较高Al 2 O3-GdAlO 3相边界能的颗粒经历与界面线缺陷（例如断开）介导的界面通量相关的间歇性刚体运动。在这些相对快速的刚体运动事件之间有很长的潜伏期。在每个事件的界面扩散系数同意从独立的测量界面扩散系数的界面扩散的大小。从模型实验的结果表明，毛细作用驱动的界面应变调解，例如在烧结过程中的致密化，是界面速率限制在驱动力的调查。
The sintering behavior of single Al2O3particles resting on GdAlO3is characterized using in situ transmission electron microscopy imaging. In bicrystal experiments, particles with lower Al2O3-GdAlO3phase boundary energies shrink via Ostwald ripening with no evidence of densification that would result from an atomic flux along the interface. Particles with higher Al2O3-GdAlO3phase boundary energies undergo intermittent rigid body motion associated with an interfacial flux mediated by interfacial line defects, e.g. disconnections. Long incubation periods elapse between these comparatively rapid rigid body motion events. The interfacial diffusivity during each event agrees with the magnitude of interfacial diffusion obtained from independent measurements of interfacial diffusivity. The results from the model experiments suggest that capillarity driven interfacial strain mediation, e.g. densification during sintering, is interface rate limited at the driving forces investigated.